Erysiphe betae | |
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Scientific classification ![]() | |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Leotiomycetes |
Order: | Erysiphales |
Family: | Erysiphaceae |
Genus: | Erysiphe |
Species: | E. betae |
Binomial name | |
Erysiphe betae (Vaňha) Weltzien, 1963 [1] | |
Synonyms [2] | |
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Erysiphe betae is a fungal plant pathogen. It is a species of powdery mildew found on genera including Beta, Dysphania and Spinacia that can affect crops of sugar beet, potentially causing up to a 30% yield loss. The fungus occurs worldwide in all regions where sugar beet is grown and it also infects other edible crops, e.g. beetroot.
Symptoms of E. betae are typical for species in the family, causing white powdery growth on leaves and stems of affected plants. It is the only powdery mildew species known from its hosts.
The pathogen survives overwinter through cleistothecia which are present in crop debris in the field and which contain ascospores (sexual spores). [4] Infection occurs when ascospores or conidia (asexual spores) are able to germinate and penetrate the plant's leaf. After infection, the pathogen, now growing as hyphae within the leaf, begins producing conidia on short conidiophores. Both ascospores and conidia can be the source of a primary inoculum or "first infection". The production of which type of spore is determined by weather conditions and time of year. Conidia can travel long distances through the air. [5]
Disease development is favored by high temperatures (15-28 °C) coupled with low humidity (<60% humidity), and low or no rainfall, with wind.[ citation needed ]
This fungus, like all powdery mildews, has a white powdery appearance. It appears on leaves in the summer time. Infection normally begins on older leaves, typically close to the junction between the lamina and petiole, and it develops on both ab- and adaxial surfaces.
This pathogen decreases yields in crops by the reduction of light available for photosynthesis in the leaves of plants. [4] It also causes leaf and shoot deformities. This will affect the yield and the quality of seed crops as well as visual appearance and quality of leaf crops. In the case of Erysiphe betae, entry into the cell involves both mechanical penetration and enzymatic degradation of the cuticle and the cell wall.[ citation needed ]
The fungus can produce some cell wall degrading enzymes include pectin lyases and polygalacturonases. Plants can contain an array of specialized inhibitors that counteract the effects of these enzymes.
In the case of control against Erysiphe betae, not much is known about how to totally eradicate this disease once it has taken hold of the crop. It must therefore be assumed that the best method of control is prevention. This can be done using fungicides. Some genes have been identified in wild species. [6]